51766688381 has 4 divisors (see below), whose sum is σ = 51768135132. Its totient is φ = 51765241632.

The previous prime is 51766688359. The next prime is 51766688383. The reversal of 51766688381 is 18388666715.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 41591931481 + 10174756900 = 203941^2 + 100870^2 .

It is a cyclic number.

It is not a de Polignac number, because 51766688381 - 2¹⁴ = 51766671997 is a prime.

It is a super-2 number, since 2×51766688381² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51766688381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51766688383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 668306 + ... + 741731.

It is an arithmetic number, because the mean of its divisors is an integer number (12942033783).

Almost surely, 2^51766688381 is an apocalyptic number.

It is an amenable number.

51766688381 is a deficient number, since it is larger than the sum of its proper divisors (1446751).

51766688381 is a wasteful number, since it uses less digits than its factorization.

51766688381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1446750.

The product of its digits is 11612160, while the sum is 59.

The spelling of 51766688381 in words is "fifty-one billion, seven hundred sixty-six million, six hundred eighty-eight thousand, three hundred eighty-one".